A4/Solutions/java-samples/Calculator.java
class Calculator {
    public static void main(String[] a) {
        System.out.println(new Fac().Compute(10));
    }
}

class Fac {
    public int Compute(int num) {
        int n;
        if (num < 1) {
            n = 1;
        }

        else {
            n = num * (this.Compute(new Adder().Compute(num, 0 - 1)));
        }
        return n;
    }
}

class Adder {
    public int Compute(int a, int b) {
        int result;
        result = a + b;
        return result;
    }
}